JP4868279B2 - Anti-icing device for vacuum line, polishing device using anti-icing device for vacuum line, and device manufacturing method using this polishing device - Google Patents

Description

  The present invention relates to an anti-icing device for a vacuum line, a polishing apparatus using the anti-icing device for a vacuum line, and a device manufacturing method using the polishing apparatus.

  The vacuum suction device generates suction force on the vacuum suction surface of the suction member connected to the end of the vacuum line by sucking air in the vacuum line from a vacuum source. Such a vacuum suction apparatus holds, for example, a surface plate for holding a semiconductor wafer and a polishing body to which a polishing pad is attached in a CMP (Chemical Mechanical Polishing) apparatus that performs mirror polishing of a semiconductor wafer. It is used for polishing heads.

In such a vacuum suction device, moisture may be mixed into the air sucked by the vacuum source when the vacuum suction surface is cleaned. For this reason, a water separation device is interposed in the vacuum line (see, for example, the following patent document), but depending on the usage environment (room temperature, humidity, etc.) of the device, a part of the water sucked into the vacuum line Vaporizing may lower the temperature in the vacuum line and cause the remaining moisture to freeze. In order to prevent such icing of the vacuum line, there is known a structure in which the vacuum line has a double piping structure to provide heat insulation so that the temperature in the vacuum line does not extremely decrease.
JP 2004-319903 A

  However, there is a problem in that the vacuum line having a double piping structure as described above leads to a large cost increase of the entire apparatus and a significant increase in the weight of the apparatus.

  The present invention has been made in view of such problems, and an object of the present invention is to provide an anti-icing device for a vacuum line that can prevent icing of the vacuum line with a simple configuration. It is another object of the present invention to provide a polishing apparatus using the vacuum line anti-icing device and a device manufacturing method using the polishing apparatus.

Water ice protection apparatus for a vacuum line according to the present invention, the Ri passage der air vacuum source sucks, is connected to a vacuum line connecting the vacuum source and the vacuum suction device, mixed with air sucked by the vacuum source Is an anti-icing device for a vacuum line for preventing freezing in the vacuum line, and a pure water supply line provided to branch from the vacuum line and extend between the vacuum source and the vacuum suction device , By supplying pure water into the vacuum line through the pure water supply line while being connected to the water supply line and being sucked by the vacuum source , the temperature in the vacuum line is approximately the same as that of pure water. And pure water supply means for maintaining the temperature at a predetermined temperature. In this anti-icing device for a vacuum line, it is preferable to include a pure water flow rate adjusting unit that is interposed in the pure water supply line and adjusts the flow rate of pure water supplied from the pure water supply unit into the vacuum line. .

  In addition, a polishing apparatus according to the present invention includes a surface plate that holds an object to be polished and a polishing head that holds a polishing body. In the polishing apparatus for polishing the polishing object by bringing the polishing body held by the polishing head into contact with the polishing object held on the surface plate, the polishing object holding means for holding the polishing object on the surface plate is a vacuum. It consists of a vacuum suction device that sucks a polishing object onto a surface plate by sucking air through the line, and the anti-freezing device for a vacuum line according to the present invention is applied to the vacuum line. Alternatively, the polishing body holding means for holding the polishing body on the polishing head comprises a vacuum suction device that sucks the polishing body onto the polishing head by sucking air through the vacuum line, and the vacuum line includes the above-described present invention. Such an anti-icing device for a vacuum line is applied.

  The device manufacturing method according to the present invention includes a step of polishing the surface of the object to be polished using the polishing apparatus according to the present invention.

  According to the anti-icing device for a vacuum line according to the present invention, it is possible to prevent the vacuum line from icing with a simple configuration. Further, according to the polishing apparatus of the present invention, efficient polishing can be performed. Further, according to the device manufacturing method of the present invention, the throughput of the polishing process can be improved.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. FIG. 1 shows an anti-icing device for a vacuum line according to an embodiment of the present invention and a CMP apparatus to which the anti-icing device is applied. The CMP apparatus 1 corresponds to an embodiment of a polishing apparatus according to the present invention, and is provided on a surface plate 10 that holds a semiconductor wafer W as an object to be polished in a horizontal posture, and above the surface plate 10. And a polishing tool 20.

  The surface plate 10 is attached to the upper end of a rotary column 11 provided extending in the vertical direction, and can be rotated in a horizontal plane by driving the rotary column 11 around its axis. Inside the surface plate 10, an in-surface surface vacuum pipe 12 that opens to the upper surface 10 a of the surface plate 10 is provided. The upper surface of the surface plate 10 is a vacuum suction surface that holds the semiconductor wafer W by vacuum suction.

  The polishing tool 20 includes a polishing head 21 and a polishing body 24. The polishing head 21 includes a spindle 22 extending in the vertical direction and a body portion 23 attached to the lower end of the spindle 22. The polishing body 24 includes a disk-shaped plate member 25 and a polishing pad 26 attached to the lower surface 25 a of the plate member 25, and the upper surface of the plate member 25 is held by the lower surface 23 a of the body portion 23 of the polishing head 21. The The polishing pad 26 is composed of a nonwoven fabric, urethane, or the like as a raw material, and is formed into a thin disk shape having substantially the same diameter as the plate member 25. Since the polishing pad 26 is a consumable item, it can be detachably attached to the lower surface 25a of the plate member 25 with an adhesive, a double-sided tape, or the like.

  The spindle 22 of the polishing head 21 can be moved three-dimensionally with respect to the surface plate 10 by a plurality of motors (not shown) and can rotate about its own central axis (vertical axis).

  The means (polishing object holding means) for holding the semiconductor wafer W, which is the object to be polished, on the surface plate 10 includes the vacuum source 31 and the above-mentioned vacuum tube in the surface plate opened on the upper surface (vacuum suction surface) 10a of the surface plate 10 The vacuum suction device 30 is configured to include a passage 12 and a vacuum line 32 that connects the vacuum source 31 and the in-plate vacuum pipe 12 and serves as a passage for air sucked by the vacuum source 31 (see FIG. 1). . In this embodiment, the vacuum line 32 is provided with a plurality of branch paths extending from the manifold portion 32a, and each branch path is connected to the CMP apparatus 1 described above. In addition, a water separation device that separates and removes water in the vacuum line 32 is included in the vacuum source 31.

  In order to perform mirror polishing of the semiconductor wafer W by using the CMP apparatus 1 having such a configuration, first, air in the vacuum line 32 is sucked from the vacuum source 31 to draw the semiconductor wafer W on the upper surface (vacuum suction) of the surface plate 10. Surface) 10a is vacuum-adsorbed. As a result, the semiconductor wafer W is held on the surface plate 10 so that the surface to be polished faces upward. The semiconductor wafer W is placed so that its center coincides with the rotation center of the surface plate 10. When the semiconductor wafer W is held on the surface plate 10, the surface plate 10 is rotated in the horizontal plane, and then the polishing head 21 is rotated in the horizontal plane. When the polishing head 21 starts rotating, the entire polishing head 21 is lowered, and the polishing pad 26 is brought into contact with the surface to be polished of the semiconductor wafer W from above. When the polishing pad 26 comes into contact with the surface to be polished of the semiconductor wafer W and polishing of the semiconductor wafer W starts, the entire polishing head 21 is arranged in a direction parallel to the contact surface between the semiconductor wafer W and the polishing pad 26 (that is, in the horizontal direction). The entire surface to be polished is polished by swinging and moving. During polishing of the semiconductor wafer W, slurry (polishing liquid) is supplied onto the surface to be polished of the semiconductor wafer W from a slurry supply device (not shown). As described above, the surface to be polished of the semiconductor wafer W held on the surface plate 10 receives the supply of the polishing liquid, and rotates and shakes the semiconductor wafer W itself and the polishing head 21 (that is, the polishing pad 26). The entire surface is uniformly polished by the dynamic motion, and the surface to be polished of the semiconductor wafer W is flattened (mirror polished) with high accuracy.

  The vacuum line 32 is provided with an anti-icing device 40 for preventing moisture mixed in the air sucked by the vacuum source 31 from freezing in the vacuum line 32. As shown in FIG. 1, the anti-icing device 40 of the vacuum line 32 has a pure water supply line 41 that is branched and extended from the vacuum line 32 and a pure water supply line 41 through the pure water supply line 41. A pure water supply source (pure water supply means) 42 that supplies water and a pure water that is interposed in the pure water supply line 41 and adjusts the flow rate of pure water supplied from the pure water supply source 42 into the vacuum line 32. And a flow rate adjusting valve (pure water flow rate adjusting means) 43.

  The pure water is supplied from the pure water supply source 42 into the vacuum line 32 after the air in the vacuum line 32 starts to be sucked by the vacuum source 31. The pure water supplied to the inside of the vacuum line 32 is sucked together with air by the vacuum source 31, and toward the vacuum source 31 side in the region between the connection portion of the pure water supply line 41 and the vacuum source 31 in the vacuum line 32. A flow of flowing pure water is formed (see an anti-icing target region shown in FIG. 1). In the region in the vacuum line 32 where the flow of the pure water is formed, the temperature is maintained at a temperature substantially the same as that of the pure water, so that moisture mixed in the vacuum line 32 is not vaporized, Freezing is prevented.

  Here, when the flow rate of pure water supplied into the vacuum line 32 from the pure water supply source 42 is too small, the temperature in the vacuum line 32 cannot be maintained at a temperature substantially the same as that of pure water. Therefore, the flow rate of pure water supplied from the pure water supply source 42 into the vacuum line 32 is adjusted by the pure water flow rate adjustment valve 43 described above. The pure water flow rate adjusting valve 43 is composed of, for example, an electromagnetic proportional control valve capable of linear flow rate control (see FIG. 1), and the pure water supply source 42 is controlled by controlling the drive amount of the spool from a control device (not shown). The flow rate of pure water supplied into the vacuum line 32 is adjusted. Here, whether or not pure water having an appropriate flow rate is supplied by the pure water flow rate adjustment valve 43 is provided on the downstream side (vacuum source 31 side) of the pure water flow rate adjustment valve 43 in the pure water supply line 41. The above-described control device determines based on the flow rate of pure water measured by the flow meter 44. Then, the control device controls (feedback control) the spool operation of the pure water flow rate adjustment valve 43 so that the pure water flow rate becomes an appropriate value. Note that an appropriate flow rate of pure water that can sufficiently prevent the temperature in the vacuum line 32 from being lowered is determined in advance through experiments and the like.

  The temperature of the pure water supplied from the pure water supply source 42 is preferably normal temperature (about 20 to 25 ° C.), but is not particularly limited as long as the water mixed in the vacuum line 32 does not freeze. However, when the temperature of the pure water is considerably lower than the normal temperature, the supplied pure water itself is likely to freeze, so it is necessary to increase the flow rate of the pure water supplied into the vacuum line 32.

  As shown in FIG. 1, a vacuum gauge (pressure sensor) 46 is provided in the vacuum line 32 so that the pressure in the vacuum line 32 can be measured. Information detected by the vacuum gauge 46, that is, the pressure in the vacuum line 32 is input to the control device described above, and the control device can detect the pressure in the vacuum line 32 based on the detection information from the vacuum gauge 46. When it is detected that the pressure is higher than the predetermined pressure (the degree of vacuum is small), it is determined that the vacuum suction operation itself by the vacuum source 31 has been stopped, or a trouble has occurred in the vacuum system, and pure water The supply of pure water from the supply source 42 into the vacuum line 32 is stopped. This is because if pure water that is sucked by the vacuum source 31 and does not form a flow is supplied into the vacuum line 32, the inside of the vacuum line 32 is filled with pure water, causing the device to malfunction. .

  As described above, the anti-icing device 40 of the vacuum line 32 shown in the present embodiment supplies pure water into the vacuum line 32 via the pure water supply line 41 branched and extended from the vacuum line 32. The pure water supplied to the vacuum line 32 is sucked by the vacuum source 31 and flows to the vacuum source 31 side, and a pure water flow toward the vacuum source 31 side is formed in the vacuum line 32. As a result, the vacuum line 32 (an area to be prevented from freezing) is maintained at a temperature substantially equal to that of pure water (that is, a temperature at which no freezing occurs in the vacuum line 32). For this reason, icing in that region is prevented, and the occurrence of inconveniences such as clogging of the vacuum line 32 and increase in suction resistance during vacuum suction can be prevented. Further, the configuration is simpler than the conventional vacuum line having a double piping structure, and the cost increase and weight increase can be suppressed. Further, according to the polishing apparatus (CMP apparatus 1 in this case) provided with such an anti-icing device 40 for the vacuum line 32, it is possible to perform efficient polishing.

  Next, an embodiment of a device manufacturing method according to the present invention will be described. FIG. 2 is a flowchart showing a semiconductor device manufacturing process. When the semiconductor manufacturing process is started, first, in step S200, an appropriate processing process is selected from the following steps S201 to S204, and the process proceeds to any step. Here, step S201 is an oxidation process for oxidizing the surface of the wafer. Step S202 is a CVD process for forming an insulating film or a dielectric film on the wafer surface by CVD or the like. Step S203 is an electrode forming process for forming electrodes on the wafer by vapor deposition or the like. Step S204 is an ion implantation process for implanting ions into the wafer.

  After the CVD process (S202) or the electrode formation process (S203), the process proceeds to step S205. Step S205 is a CMP process. In the CMP process, the above-described polishing apparatus (CMP apparatus 1) according to the present invention performs planarization of the interlayer insulating film, polishing of the metal film on the surface of the semiconductor device, formation of damascene by polishing of the dielectric film, and the like. .

  After the CMP process (S205) or the oxidation process (S201), the process proceeds to step S206. Step S206 is a photolithography process. In this step, a resist is applied to the wafer, a circuit pattern is printed on the wafer by exposure using an exposure apparatus, and the exposed wafer is developed. Further, the next step S207 is an etching process in which a portion other than the developed resist image is etched away, and then the resist is peeled off to remove the unnecessary resist after etching.

  Next, it is determined in step S208 whether all necessary processes are completed. If not completed, the process returns to step S200, and the previous steps are repeated to form a circuit pattern on the wafer. If it is determined in step S208 that all processes have been completed, the process ends.

  Since the device manufacturing method according to the present invention includes a step of polishing the surface of the semiconductor wafer W using the polishing apparatus (CMP apparatus 1) according to the present invention in the CMP step, the polishing step (CMP step). Throughput is improved. Thereby, there is an effect that a device (here, a semiconductor device) can be manufactured at a low cost as compared with the conventional device manufacturing method. Note that the polishing apparatus (CMP apparatus 1) according to the present invention may be used in a CMP process of a semiconductor device manufacturing process other than the semiconductor device manufacturing process. Moreover, since the semiconductor device manufactured by the device manufacturing method according to the present invention is manufactured at a high throughput, it becomes a low-cost semiconductor device. The device manufacturing method according to the present invention can of course manufacture devices other than semiconductor devices at a low cost by using an object to be polished other than a semiconductor wafer, such as a liquid crystal substrate.

  Although the preferred embodiments of the present invention have been described so far, the scope of the present invention is not limited to those shown in the above-described embodiments. For example, in the above-described embodiment, an example in which the anti-icing device for a vacuum line according to the present invention is applied to a vacuum suction device that constitutes a polishing object holding unit that holds a semiconductor wafer W (polishing object) on the surface plate 10. Although the means for holding the polishing body 24 on the polishing head 21 (polishing body holding means) is constituted by a vacuum suction device, the anti-freezing device for a vacuum line according to the present invention is applied to the vacuum suction device. It is also possible. In this case, the vacuum suction device constituting the polishing body holding means is connected to, for example, a polishing head vacuum line extending inside the polishing head 21 and opening to the lower surface 23a of the barrel 23, and this polishing head vacuum line. A vacuum line, and by sucking air through the vacuum line, the polishing body 24 is vacuum-sucked to the lower surface (vacuum suction surface) 23a of the body portion 23 of the polishing head 21.

  Further, the polishing apparatus to which the anti-icing device for a vacuum line according to the present invention is applied is not limited to the above-described CMP apparatus 1 and can be applied to other polishing apparatuses. Furthermore, as long as the apparatus is provided with a vacuum line, the anti-icing device for a vacuum line according to the present invention can be applied to apparatuses other than the polishing apparatus.

1 is a diagram illustrating a configuration of an anti-icing device for a vacuum line according to an embodiment of the present invention and a CMP apparatus to which the anti-icing device is applied. It is a flowchart which shows an example of the device manufacturing method which concerns on this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 CMP apparatus 10 Surface plate 21 Polishing head 24 Polishing body 30 Vacuum suction apparatus 31 Vacuum source 32 Vacuum line 40 Anti-icing device 41 Pure water supply line 42 Pure water supply source 43 Pure water flow control valve W Semiconductor wafer

Claims (5)

Ri passage der air vacuum source sucks, is connected to a vacuum line connecting the vacuum source and the vacuum suction device, water mixed in the air sucked by the vacuum source is prevented from freezing in the vacuum line An anti-icing device for a vacuum line for
A pure water supply line provided to extend from the vacuum line between the vacuum source and the vacuum suction device ;
By supplying pure water into the vacuum line via the pure water supply line while being connected to the pure water supply line and being suctioned by the vacuum source , the temperature in the vacuum line is increased. An anti-icing device for a vacuum line, comprising pure water supply means for maintaining a temperature substantially the same as that of pure water.   The pure water flow rate adjusting means is provided in the pure water supply line and adjusts the flow rate of pure water supplied from the pure water supply means into the vacuum line. Anti-freezing device for vacuum line. A polishing plate for holding the polishing object; and a polishing head for holding the polishing body, wherein the polishing body held by the polishing head is brought into contact with the polishing object held on the platen to In a polishing apparatus that performs polishing,
The polishing object holding means for holding the polishing object on the surface plate comprises a vacuum suction device for vacuum-adsorbing the polishing object on the surface plate by sucking air through a vacuum line, and the vacuum line A polishing apparatus, wherein the anti-icing device for a vacuum line according to claim 1 is applied. A polishing plate for holding the polishing object; and a polishing head for holding the polishing body, wherein the polishing body held by the polishing head is brought into contact with the polishing object held on the platen to In a polishing apparatus that performs polishing,
The polishing body holding means for holding the polishing body on the polishing head includes a vacuum suction device that sucks air onto the polishing head by sucking air through a vacuum line, and the vacuum line includes the vacuum suction device. A polishing apparatus to which the anti-icing device for a vacuum line according to 1 or 2 is applied.   A device manufacturing method comprising a step of polishing the surface of the object to be polished using the polishing apparatus according to claim 3.

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